For several decades microscopy and tomography were designed using scanning approaches; see Theodore George Rochow and Eugene George Rochow, “An introduction to microscopy by, means of light, electron, X ray, or ulrasound” Plenum Press, 1978. This made acquiring the data on a pixel by pixel basis a time consuming process. For many industrial applications this can be very costly.
The general feature which unifies all microcopies and tomographies, is a modulated or pulsed focussed pencil probe beam that is detected and sent to deflection sensor then demultiplexer (time, heterodyne) to extract the required information for building the image See Kyuman Cho, David L. Mazzoni and Christopher C. Davis, “measurement of local slope of a surface by vibrating-sample heterodyne interferometry: A new method for scanning microscopy. Optics Letters, Vol. 18 Issue 3 Page 232, T. Sawatari Optical heterodyne scanning microscope. Appl. Opt. 12, 2768-2772 (1973).
A significant part of the scientific and industrial community has been attempting to improve the performance within these lines of design. Some scientists proposed using several beams focused into the sample utilizing a lens array; Martin Schrader, Rainer Pick, Stefan, W. Hell “New development in 4Pi-microscopy”, OSA meeting, 1998, Paper WM3.
Others utilized the possibility of focusing an array of diode lasers into the sample; Even though there was a significant reduction in the data acquisition time, these approaches were not applicable with ultra high-resolution microscopes such as atomic force microscopes; see H. Kumar Wickramasinghe. Scanned-probe Microscopes “Scientific American”48-55. and near field microscopies; E. Betzing, J. K. Trautman, J. S. Weiner, T. D. Harris and R. Wolf, Polarization contrast in near-field scanning optical microscopy, Appl. Opt. 4563-4568, (1992).
The present invention a general purpose optical microscopic-tomographic system proposed here is based on using different form of 2-D image multiplexer for performing 2-D image data acquisition. The 2-D image multiplexer can be 2-D homodyne heterodyne detection, 2-D time-division demultiplexing, 2-D wavelength division demultiplexing or any combination
This system can be cascaded with many microscopies and tomographic systems. This includes Doppler X. J. Wang, T. E. Milner and J. S Nelson, “Charactarization of fluid flow velocity by optical Doppler tomography,” Opt. Letts.20,1337 (1995), photon density J. B. Fishkin, E. Gratton, J.Opt.Soc.Am.A. 10. 127-140 (1993)., phothermal Amer, N. M. J. Phys (Paris) Colloq. C6, 185, ultrasonic Clavin F. Quate , “The acoustic Microscope,” Scientific american, 31-39, surface profilometry. Kyuman Cho, David L. Mazzoni and Christopher C. Davis, “measurement of local slope of a surface by vibrating-sample heterodyne interferometry: A new method for scanning microscopy. Opt. letts., and atomic force microscopy H. Kumar Wickramasinghe. Scanned-probe Microscopes “Scientific American, 48-55.
The present invention provides new systems that are the first non-scanning systems which has potential for data acquisition at speeds even faster than camera frame speeds. Further, because the system uses a plane wave for probing the media and does not use a focused beam, this means that the resolutions are not limited by the focusing ability of the lens as in conventional microscopes; see Theodore George Rochow and Eugene George Rochow, “An introduction to microscopy by, means of light, electron, X-ray, or ulrasound” Plenum Press, 1978; or the sharpness of the tip in near field microcopies; see H. Kumar Wickramasinghe. Scanned-probe Microscopes “Scientific American, 48-55. Hence present invention system has a potential for attaining as high a resolution as near field microscopy http://www.research.ibm.com/research/press/optical1.html., This feature assumes that appropriate optical design has been done to overcome the aberration of lenses. To overcome the aberration from high magnification, a feedback magnification system is introduced. The magnification in each loop should be made small to avoid aberration. Through feedback of the inputs several times a high magnification is achieved. Further a specific implementation based on volume Bragg grating can also remove a certain portion of the aberration and hence the resolution can be improved. This feature applies for both scanning and non-scanning systems.
Because the new system of the present invention operates in parallel, this opens the possibility of using a Fourier optical processor for optical system aberration correction and medium turbulence compensation. Also, getting rid of the unmodulated portions of the light, opens the possibility for very high sensitive microscopy-tomography., a problem which faced other researchers in this area; see Thomas C. Hale, Kenneth L. Telschow and Vance A. Deason., “Photorefractive optical lock-in vibration spectral measurement.,” Appl. Opt. 36, 8248-8257 (1997); Kyuman Cho, David L. Mazzoni and Christopher C. Davis, “measurement of local slope of a surface by vibrating-sample heterodyne interferometry: A new method for scanning microscopy. Optics Letters, Vol. 18 Issue 3 Page 232.
Numerous forms of 2-D image demultiplexers can be used for this application. However, we are going to describe some of the preferred designs. The first proposed design is based on smart pixilated structure, the second is based on demultiplexing light with a reference signal via a tunable Bragg grating. The third is simply an image intensifier with modulated gain. (U.S. Pat. No. 5,213,105 by Gratton, et, al), The fourth is CCD camera which acts as electronic hologram, and the fifth is based on using a demultiplexer of real-time holographic media. See for example J. Khoury, V. Ryan C. L. Woods and M. Cronin-Golomb “Photorefractive optical lock-in detector,” Opt. Letts, 16, 1442-1444, 1991.
Many communities will benefit from this design: (1) the microelectronic community in accelerating the process of checking wafers and electronic chips, (2) the medical community in tomographic applications for detecting tumors in abnormal tissues.(3) The biological community (4) the automobile and other industrial communities.